There is an increasing interest in building integrated photovoltaic systems (BIPV). In one type of BIPV, flexible solar panels are adhered directly onto the exterior of building surfaces. The exterior building surface may be a thermoplastic olefin (TPO) membrane. The only commercial flexible solar panels that are readily available in significant volumes are from UniSolar. However, other similar panels are becoming more readily available from other manufacturers, such as Ascent Solar and Fuji Electric Systems.